$$x^5+3x^3y^2+3xy^4$$

$$8x+\frac{3}{2}x^4=0$$

$$x^3y-x-8y-12=0$$

$$100\left(-1\right)\left(2\right)$$

$$2x^2+3y^2+5z^2=900$$

$$\left(-4\right)\:\left(-2\right)\:\left(10\right)\:\left(-1\right)$$

$$\frac{\cos^2x}{1-\sin x^2}=1$$